This calls for your own personal taste since the best techniques for feeding baby are really yours to choose. It doesn’t matter whether you feed baby sitting up, on your side or when lying down. But the golden rule to remember is that you and your baby have to be COMFORTABLE.
You need to get your positioning right. These are your posture, how you hold your baby and how your baby takes your breast.Your Posture

Make yourself comfortable. Your baby needs to be well supported. You may want to consider sitting up in bed, back well supported with baby’s head resting in the crook of your arm OR sitting on a chair with your back supported.

Make sure you are not leaning back so that your breasts are not pulled away from your baby and out of his mouth while he tries to feed – or hunched over.

Use props for support. Have as many pillows, cushions or soft, firm supports (such as folded rugs or blankets as well as whatever you may need to support your feet) as you need, to support both you and your baby.

How To Hold Your Baby
In summary, the important points to remember about how you hold your baby are that your baby:

is held close to you

is well supported

is facing you

has his mouth just below your nipple as you prepare to feed

has his head, neck and back all in a straight line

Make sure his arms and hands do not get in the way as he goes on to feed.

How Your Baby Takes Your BreastMake sure your baby takes your breast; do not try to give it to him or push your breast into his mouth.
As your baby goes on your breast, check that he:

gapes his mouth wide open

takes as much as possible of brown area (areola) around the nipple damaged because it is so far back in the baby’s mouth that there is no friction against it. (It is friction that causes both soreness and damage to the nipple). This is why breast feeding should not hurt.

In the accompanying diagram, you can see what is going on inside your baby’s mouth when breast feeding is going well.

Here is what your baby should look like when he is feeding well.

Notice

His chin is against the breast.

His mouth is open wide and the lower lip is pressed down and back against his chin.

His nose lies right against your breast. Notice that his nose lies on the surface of your breast and he is free to breathe. You do not need to hold your breast away from his nose.